(Proverbs 4:7 KJV) Wisdom is the principal thing; therefore get wisdom: and with all thy getting get understanding.
How do we acquire something this important? Start small and at the beginning. When I need to tutor someone in Algebra or Geometry I realize that I have not had a math class in over 40 years. I find that if the student is in the middle of the book, I am lost. If they are at the beginning of the book, I have not problem. If I work through the chapters with them it all comes back. So start as a beginner. That seems obvious but we want to be experts at once. Before you can make award winning spaghetti, you have to know how to boil water.
Where do I start? Not in a systematic theology. Not in the book or Revelation. Nor in Romans. Start reading a gospel. Mark is the shortest. Look at the cross references and follow a few thoughts through the Bible. When you find another place that is interesting, read the context. Start small, but start.